In short, the effectiveness of Natural Cycles remains the same whether you use an oral basal thermometer, the Oura Ring, or the Apple Watch. Natural Cycles is 93% effective with typical use and 98% effective with perfect use.
Natural Cycles received FDA clearance and CE marking to use the Oura Ring as an input to the NC° app. In order to obtain these regulatory clearances, we conducted a clinical study to demonstrate that a new temperature data source is safe and effective for use with the Natural Cycles main algorithm.
In the study, we compared the temperature trend data from the Oura Ring with temperature data from a basal thermometer. The results showed that there was no significant difference in day-to-day variations in temperature measurements during the follicular and luteal phases in a monthly cycle when Natural Cycles was used with a basal thermometer versus a continuous measuring device (the Oura Ring). Additionally, there have been no changes to how the Natural Cycles algorithm detects ovulation nor how it determines the daily fertility status.
These results show that Natural Cycles provides equivalent daily fertility information regardless of whether you’re using a thermometer, an Oura Ring, or the Apple Watch. For more information on this, please continue reading here.
The biggest difference when using an Oura Ring as opposed to an oral thermometer is that you don’t have to remember to measure your temperature every morning when you first wake up. To learn more about how the Oura Ring works with Natural Cycles, please read here.